Instant Webservers! Just add electrons!
All these run on localhost:8000 unless otherwise noted and serve the
index.html file in the current directory in an insecure session, i.e, open http://127.0.0.1:8000 in any browser. All except Python's SimpleHTTPServer allow multiple simultaneous client connections. The Node
http-server module is the most robust although none of these is suitable for production. The true one-liners (all but Node) should all run without any dependencies on a standard OS X or Linux install.
python -m SimpleHTTPServer
python2 -m SimpleHTTPServer